Hemispheric color differences on Saturn's moon Rhea are apparent in this false-color view from NASA's Cassini spacecraft in this March 2, 2010 file photo. (Photo by Reuters/NASA/JPL/SSI)

Spur Lacasse of Cochrane, Alberta rides the horse Rebel Warrior in the novice bareback event during the Calgary Stampede rodeo in Calgary, Alberta, in this July 12, 2014 file photo. (Photo by Todd Korol/Reuters)

A U.S. Army soldier with the 10th Special Forces Group and his military working dog jump off the ramp of a CH-47 Chinook helicopter from the 160th Special Operations Aviation Regiment during water training over the Gulf of Mexico as part of exercise Emerald Warrior 2011 on March 1, 2011. (Photo by Tech. Sgt. Manuel J. Martinez/U.S. Air Force)

An internally displaced Afghan girl holds a child at a refugee camp in Kabul, Afghanistan May 31, 2016. (Photo by Mohammad Ismail/Reuters)

In this July 24, 2016 photo, a pilgrim takes a bath in a sacred mud pool during the annual Voodoo celebration in Plaine-du-Nord, Haiti, Saturday, July 23, 2016. Pilgrims come to bathe in the mud and make offerings expecting a miracle. (Photo by Dieu Nalio Chery/AP Photo)

Chocolate is the greatest gift the Earth has given us. The dessert table would be a sad sight without it. It’s so beloved, so appreciated, that the Swedish scientist who named the cocoa plant that gives us chocolate called it Theobroma cacao, which means “food of the gods”. Here: Farmer holding a freshly cut cocoa bean pod, revealing the pulp and seed inside on a rainforest farm. (Photo by Doug McKinlay/Getty Images)

The Arcaid awards highlight the best architectural photographs of the year – pictures of everything from giant arenas to tiny huts. The shortlisted photographs will be exhibited at the World Architecture Festival in Berlin, from 16 to 18 November, with an overall winner announced during the event’s gala dinner. Here: The stage for Haduwa Arts & Culture Institute, Ghana. Architect: (applied) Foreign Affairs. Nominated in the Sense of Place category. The open-air auditorium of this arts institute in Apam, Ghana, is built from ultra-strong curved bamboo. (Photo by Julien Lanoo)

People and sea-gulls bathe in the sea as the sun goes up with red colors in Stralsund close to the baltic sea island of Rügen, on early November 23, 2016. (Photo by Stefan Sauer/AFP Photo/DPA)